阵列型导航天线相位中心控制及群时延校正

Phase Center Control and Group Delay Correction of the Antenna Array

导航接收机采用阵列天线波束形成零陷干扰，获得对卫星信号的优质接收，以提高导航定位性能。为了获得更高的导航定位性能，需要校正阵列天线波束形成相位中心变化和群时延波动。本文提出幅相建模改进的MVDR波束形成算法，其指向有用信号方向的载波相位恒为零，实现了对相位中心的控制；波束形成后频带内的相位数据进行差分拟合可以得到群时延特性，进而可对波束形成指向不同方向引起的群时延波动进行校正。仿真得到有用信号方向上阵列天线群时延引入的接收机伪距测量零值，用其进行伪距测量值校正可达1cm的精度。该方法解决了阵列天线波束形成相位中心变化和群时延波动的校正问题，可为高性能导航应用提供技术储备。

In order to improve the navigation performance, the receiver adopts the antenna array to create null interferences and obtain high quality satellite navigation signal. To pursue the higher performance, the phase center variation （PCV） and the group delay （GD） after antenna array beam forming must be corrected. The radiation pattern including improved Minimum Vari- ance Distortionless Response（ MVDR） algorithm beam forming is put forward in this paper. The phase in the useful signal direc- tion after beam forming is zero and the phase center is under control. The GD is obtained through the differentiate fitting of the phase data in the frequency band after beam forming, and then the GD in different directions can be corrected. The pseudo - range measurement null value is introduced by the GD in the useful signal direction through simulation, with which the correction accuracy is within 1cm. In this way, the problem of phase center variation correction and the group delay correction after beam forming is resolved, and the technique can support the high performance satellite navigation application.